1. Field of the Invention
This invention relates to a built-up furniture unit, and more particularly to built-up furniture units whose side panels are formed by housing panels which are formed into a hollow double-walled construction by blow molding a thermoplastic resin, such as wagons, portable or stationary type cabinets, racks, desks, chests and work tables and the like for home use, industrial use, office-work use, etc.
2. Description of the Prior Art:
Examples of the built-up furniture unit of the kind specified above include a container as disclosed in Japanese Utility Model Application Laid-open Publication NO. SHO 62-200541 and a built-up construction of as desk panel as disclosed in Japanese Utility Model Application Laid-Open Publication NO. SHO 64-21618, etc.
In any of the above-mentioned prior art examples, since the portions of the housing panels to be joined to each other are formed in such a construction as to be joined by fitting tongues formed on one of them into grooves formed on the other, when the housing panels are subjected to a loading, the joined portions are deformed, rubbing or chafing against each other, which results in offensive creak from the joined portions thus displeasing the user.
Moreover, there has been a problem in that the joined portions are inadequate in mechanical strength.
Light-weight having panels for use in built-up furniture units which possess a relatively excellent rigidity can be obtained by blow molding a thermoplastic resin into a hollow doubled-walled construction, however, there is a problem in that they are not satisfactory as structural members. Therefore, even in housing panels formed by a material which is excellent in mechanical strength, it is very difficult to completely eliminate "deformation due to deflection" and "tottering from side to side" of them when subjected to loading. In the jointed construction of the above-mentioned prior art built-up furniture units, it is envisaged that when the above-mentioned deformation occurs the joined portions of the housing panels will rub against each other while they are kept in pressure contact, thus creating the above-mentioned creak.